EP3368279B1 - Part manipulation using printed manipulation points - Google Patents

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATION
• The present invention is part of a patent application claiming the priority benefit of
• U.S. Patent Application No. 62/248,758, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,765, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,770, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,776, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,783, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,791, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,799, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,966, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,968, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,969, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,980, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,989, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,780, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,787, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,795, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,821, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,829, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,833, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,835, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,839, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,841, filed on October 30, 2015,
• U.S. Patent Application No. 62/248,847, filed on October 30, 2015, and
• U.S. Patent Application No. 62/248,848, filed on October 30, 2015.
TECHNICAL FIELD
• The present invention relates generally to a method for the manipulation of parts in an additive manufacturing systems. According to the present invention, a robot arm (as manipulator device) interfaces with permanent or temporary manipulator points defined in, or associated with, the part.
BACKGROUND
• Automated or robotic manipulation methods are being increasingly used in manufacturing and industry. A wide variety of automated manipulators with various articulation and degrees of motion are available. Such manipulators can include simple Cartesianx-y-z translations using linear slides, SCARA (Selective Compliance Articulated Robot Arm) able to dox-y-z and rotational movements, or articulated manipulators with six degrees of freedom or more. Automated manipulators can operate continuously for long durations of time, in hostile environmental conditions, and with precision and weight handling ability that is difficult or impossible for human workers to match.
• Another technique increasingly used in manufacturing and industry is known as additive manufacturing. Additive manufacturing, also referred to as 3D printing, typically involves sequential layer by layer addition of material to build a part. Beginning with a 3D computer model, an additive manufacturing system can be used to create complex parts from a wide variety of materials. One additive manufacturing technique known as powder bed fusion (PBF) uses one or more focused energy sources, such as a laser or electron beam, to draw a pattern in a thin layer of powder by melting the powder and bonding it to the layer below.
• Shkolnik et al.,US 2010/0262272 A1, describe a method and apparatus for making a three-dimensional object from a solidifiable material such as a photopolymer. In the method, positions relative to a build axis are subdivided into first and second exposure data subsets. The first and second exposure data subsets are solidified in alternating sequences to reduce the surface area of solidified material in contact with a solidification substrate.
• El-Dasher et al.,US 2014/0252687 A1, describe a system for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system uses a diode array to generate an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.
• Kemmer et al., US 2015/0076732 A1, describe an extended structure additive manufacturing device and method, wherein the device includes a movable material bonding component and a movement mechanism which enable the device to create parts outside the conventional additive manufacturing device print volumes defined by the device and its printhead. Therein, methods of making parts involve creating a portion of a part and moving the extended structure additive manufacturing device relative to the part and printing a second portion of the part. Therein, parts incapable of being formed using a conventional additive manufacturing device may be made using the extended structure additive manufacturing device and/or methods.
• Abe et al., US 2006/0192322 A1, describes an apparatus for making a three-dimensional object. The apparatus includes a powdery layer-forming unit for forming a powdery layer on a table and an optical beam-irradiating unit for irradiating an optical beam on a predetermined region of the powdery layer to sinter the predetermined region. The optical beam-irradiating unit is disposed at a position spaced from immediately above an optical beam-irradiating range to obliquely irradiate the optical beam on the powdery layer. Because fumes generated by irradiating and heating the powdery layer with the optical beam rise towards a position immediately above them, the optical beam is irradiated from the position spaced from immediately above the optical beam-irradiating range, thereby reducing a cloud of the optical beam-irradiating unit that may be caused by the fumes.
• Ederer,US 2012/0113439 A1, teaches a method for producing three-dimensional components, using a three-dimensional printing method, an auxiliary structure being additionally formed beyond an extension of the one or more components during the construction of components, wherein an auxiliary structure for components produced by means of three-dimensional printing methods is provided, the auxiliary structure being constructed along with the component and extending beyond a dimension of the one or more components.
• Refle et al., DE 10 2007 048 385 B3, teaches a method of producing at least one component by means of a generative manufacturing process, including selective laser sintering (SLS), 3-D printing processes or fused deposition modeling (FDM). In the described method at least one molded part is produced together with the component by way of the one generative manufacturing process, which serves for purposes of a gripping subsequent to the generative manufacturing process as well as a subsequent component handling, wherein either the at least one molded part is formed in a lattice- or mesh-like manner such, that the component is at least partially surrounded by the molded part, so that the component is gripped exclusively by handling the molded part surrounding the component, or the at least one molded part is designed in the manner of at least two gripper jaws which can be placed against the component in such a way that the gripper jaws are brought into form-fit and/or force-fit engagement with the component by means of a manipulator unit.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A illustrates an additive manufacturing system;
• FIG. 1B is a top view of a structure being formed on an additive manufacturing system;
• FIG. 2 illustrates an additive manufacturing method;
• FIG. 3A is a cartoon illustrating an additive manufacturing system including lasers;
• FIG. 3B is a detailed description of the light patterning unit shown inFIG. 3A.;
• FIG. 3C is one embodiment of an additive manufacturing system with a "switchyard" for directing and repatterning light using multiple image relays;
• FIG. 3D illustrates a simple mirror image pixel remapping;
• FIG. 3E illustrates a series of image transforming image relays for pixel remapping;
• FIG. 3F illustrates an patternable electron energy beam additive manufacturing system;
• FIG. 3G illustrates a detailed description of the electron beam patterning unit shown inFIG. 3F;
• FIG. 4A illustrates an additively manufactured collection of parts supported by a surrounding additively manufactured structure able to act as a manipulation point;
• FIG. 4B illustrates an additively manufactured structure with additively manufactured manipulation points;
• FIG. 5A illustrates a robot arm grasping a part by an additively manufactured manipulation point;
• FIG. 5B illustrates a robot arm lifting and reorienting a part by its additively manufactured manipulation point;
• FIG. 5C illustrates a robot arm moving the part held by its additively manufactured manipulation point to another processing area as covered by the appended claims;
• FIG. 6 illustrates a part including various possible additively manufactured manipulation points; and
• FIG. 7 is a flowchart illustrating one embodiment of a method for manufacturing that use manipulation points.
SUMMARY
• The invention is defined by the independent claim. Dependent claims specify embodiments thereof.
DETAILED DESCRIPTION
• In the following description, reference is made to the accompanying drawings that form a part thereof, and in which is shown by way of illustrating specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the concepts disclosed herein, and it is to be understood that modifications to the various disclosed embodiments may be made, and other embodiments may be utilized, without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense.
• An additive manufacturing system that supports or accommodates use of various features and elements to enable manufacture various parts, components, structures, frames, trusses, lattices, columns, tubes, beams, airfoils, blades, propellers, and the like is discussed in the following. Such structures, components, or complete units (collectively described herein as "parts") can be formed from at least one of a metal, metal hybrid material, ceramic, ceramic hybrid material, glass, glass hybrid material, plastic, plastic hybrid material, or other material or combination of materials that are capable of melting; and substantially formed using only an additive manufacturing system. These parts can include temporary or permanent structures, also additively manufactured, that can act as manipulation points. Such structures can include but are not limited to, sprues, lips, extensions, pads, notches, gaps, cavities, lands, or the like. In some embodiments, optical or imaging sensors can be used to identify guide or indicial marks defined on the part or a manipulation point to allow for precise three-dimensional location of the part. According to the invention, the additive manufacturing system has an energy source that can support multiple energy beams, and an energy patterning unit that can include a transmissive or reflective optically addressed light valve to allow high throughput processing that can be aided by use of a robot arm.
• In certain embodiments discussed herein, increasing throughput of manufactured parts using additive manufacturing techniques can benefit from use of automated manipulation technology. The manufacturing method according to the invention includes the steps of providing a powdered material; providing an energy source that can include multiple semiconductor lasers; and directing a beam from the energy source toward an energy patterning unit. The energy patterning unit can include an optically addressed light valve or other patterning mechanism to form a two-dimensional patterned energy beam, which is directed against the powder material to form a part having a printed manipulation point. To improve processing flexibility and manufacturing throughput, an automated manipulator being a robot arm is used to engage the manipulation point. In some embodiments, further processing steps could include removing the manipulation point, mechanically or with a directed energy beam. The part having a manipulation point is then moved to another processing area by the automatic manipulator.
• Parts can include additively printed structures formed from at least one of a metal, ceramic, or metallo-ceramic material. The parts are formed using only an additive manufacturing system that includes a two-dimensional patterned energy beam. The parts further have one or more manipulation points capable of being engaged by a manipulator device. The manipulation points can be structures projecting from the part or structures defined within the part, including cavities, notches, lands, or holes. In those embodiments with projecting parts, the manipulation point can be a temporary structure removable with, for example, a mechanical clipper or directed energy beam.
• Another described embodiment is a method of manufacturing a part by providing a powder material selected from at least one of a metal, ceramic, or metallo-ceramic material. A part is substantially additively manufactured to have a manipulation point, with the part being movable using a manipulator to engage the manipulation point. In some embodiments, additive manufacturing can involve use of an energy source that includes multiple lasers. The lasers collectively form a beam directed from the energy source toward an energy patterning unit that includes an optically addressed light valve, forming a two-dimensional patterned energy beam. This two-dimensional patterned energy beam is directed against the powder material to form the part with the defined manipulation point.
• As seen inFIG. 1, anadditive manufacturing system 100 has anenergy patterning system 110 with anenergy source 112 that can direct one or more continuous or intermittent energy beam(s) towardbeam shaping optics 114. After shaping, if necessary, the beam is patterned by anenergy patterning unit 116, with generally some energy being directed to a rejected energy handling unit 118. Patterned energy is relayed byimage relay 120 toward anarticle processing unit 140, typically as a two-dimensional image 122 focused near abed 146. The bed 146 (with optional walls 148) can form achamber containing material 144 dispensed bymaterial dispenser 142. Patterned energy, directed by theimage relay 120, can melt, fuse, sinter, amalgamate, change crystal structure, influence stress patterns, or otherwise chemically or physically modify the dispensedmaterial 144 to form structures with desired properties.
• Energy source 112 generates photon (light), electron, ion, or other suitable energy beams or fluxes capable of being directed, shaped, and patterned. Multiple energy sources can be used in combination. Theenergy source 112 can include lasers, incandescent light, concentrated solar, other light sources, electron beams, or ion beams. Possible laser types include, but are not limited to: Gas Lasers, Chemical Lasers, Dye Lasers, Metal Vapor Lasers, Solid State Lasers (e.g. fiber), Semiconductor (e.g. diode) Lasers, Free electron laser, Gas dynamic laser, "Nickel-like" Samarium laser, Raman laser, or Nuclear pumped laser.
• A Gas Laser can include lasers such as a Helium-neon laser, Argon laser, Krypton laser, Xenon ion laser, Nitrogen laser, Carbon dioxide laser, Carbon monoxide laser or Excimer laser.
• A Chemical laser can include lasers such as a Hydrogen fluoride laser, Deuterium fluoride laser, COIL (Chemical oxygen-iodine laser), or Agil (All gas-phase iodine laser).
• A Metal Vapor Laser can include lasers such as a Helium-cadmium (HeCd) metal-vapor laser, Helium-mercury (HeHg) metal-vapor laser, Helium-selenium (HeSe) metal-vapor laser, Helium-silver (HeAg) metal-vapor laser, Strontium Vapor Laser, Neon-copper (NeCu) metal-vapor laser, Copper vapor laser, Gold vapor laser, or Manganese (Mn/MnCl₂) vapor laser.
1. a. A Solid State Laser can include lasers such as a Ruby laser, Nd:YAG laser, NdCrYAG laser, Er:YAG laser, Neodymium YLF (Nd:YLF) solid-state laser, Neodymium doped Yttrium orthovanadate(Nd:YVO₄) laser, Neodymium doped yttrium calcium oxoborateNd:YCa₄O(BO₃)³ or simply Nd:YCOB, Neodymium glass(Nd:Glass) laser, Titanium sapphire(Ti:sapphire) laser, Thulium YAG (Tm:YAG) laser, Ytterbium YAG (Yb:YAG) laser, Ytterbium:2O₃ (glass or ceramics) laser, Ytterbium doped glass laser (rod, plate/chip, and fiber), Holmium YAG (Ho:YAG) laser, Chromium ZnSe (Cr:ZnSe) laser, Cerium doped lithium strontium (or calcium)aluminum fluoride(Ce:LiSAF, Ce:LiCAF), Promethium 147 doped phosphate glass(147Pm⁺³:Glass) solid-state laser, Chromium doped chrysoberyl (alexandrite) laser, Erbium doped anderbium-ytterbium co-doped glass lasers, Trivalent uranium doped calcium fluoride (U:CaF₂) solid-state laser, Divalent samarium doped calcium fluoride(Sm:CaF₂) laser, or F-Center laser.
• A Semiconductor Laser can include laser medium types such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, GaInP, InGaAs, InGaAsO, GaInAsSb, lead salt, Vertical cavity surface emitting laser (VCSEL), Quantum cascade laser, Hybrid silicon laser, or combinations thereof.
• For example, in one embodiment a single Nd:YAG q-switched laser can be used in conjunction with multiple semiconductor lasers. In another embodiment, an electron beam can be used in conjunction with an ultraviolet semiconductor laser array. In still other embodiments, a two-dimensional array of lasers can be used. In some embodiments with multiple energy sources, pre-patterning of an energy beam can be done by selectively activating and deactivating energy sources.
• Beam shaping unit 114 can include a great variety of imaging optics to combine, focus, diverge, reflect, refract, homogenize, adjust intensity, adjust frequency, or otherwise shape and direct one or more energy beams received from theenergy source 112 toward theenergy patterning unit 116. In one embodiment, multiple light beams, each having a distinct light wavelength, can be combined using wavelength selective mirrors (e.g. dichroics) or diffractive elements. In other embodiments, multiple beams can be homogenized or combined using multifaceted mirrors, microlenses, and refractive or diffractive optical elements.
• Energy patterning unit 116 can include static or dynamic energy patterning elements. For example, photon, electron, or ion beams can be blocked by masks with fixed or movable elements. To increase flexibility and ease of image patterning, pixel addressable masking, image generation, or transmission can be used. In some embodiments, the energy patterning unit includes addressable light valves, alone or in conjunction with other patterning mechanisms to provide patterning. The light valves can be transmissive, reflective, or use a combination of transmissive and reflective elements. Patterns can be dynamically modified using electrical or optical addressing. In one embodiment, a transmissive optically addressed light valve acts to rotate polarization of light passing through the valve, with optically addressed pixels forming patterns defined by a light projection source. In another embodiment, a reflective optically addressed light valve includes a write beam for modifying polarization of a read beam. In yet another embodiment, an electron patterning device receives an address pattern from an electrical or photon stimulation source and generates a patterned emission of electrons.
• Rejected energy handling unit 118 is used to disperse, redirect, or utilize energy not patterned and passed through the energypattern image relay 120. In one embodiment, the rejected energy handling unit 118 can include passive or active cooling elements that remove heat from theenergy patterning unit 116. In other embodiments, the rejected energy handling unit can include a "beam dump" to absorb and convert to heat any beam energy not used in defining the energy pattern. In still other embodiments, rejected beam energy can be recycled usingbeam shaping optics 114. Alternatively, or in addition, rejected beam energy can be directed to thearticle processing unit 140 for heating or further patterning. In certain embodiments, rejected beam energy can be directed to additional energy patterning systems or article processing units.
• Image relay 120 receives a patterned image (typically two-dimensional) from theenergy patterning unit 116 and guides it toward thearticle processing unit 140. In a manner similar tobeam shaping optics 114, theimage relay 120 can include optics to combine, focus, diverge, reflect, refract, adjust intensity, adjust frequency, or otherwise shape and direct the patterned image.
• Article processing unit 140 can include awalled chamber 148 andbed 144, and amaterial dispenser 142 for distributing material. Thematerial dispenser 142 can distribute, remove, mix, provide gradations or changes in material type or particle size, or adjust layer thickness of material. The material can include metal, ceramic, glass, polymeric powders, other melt-able material capable of undergoing a thermally induced phase change from solid to liquid and back again, or combinations thereof. The material can further include composites of melt-able material and non-melt-able material where either or both components can be selectively targeted by the imaging relay system to melt the component that is melt-able, while either leaving along the non-melt-able material or causing it to undergo a vaporizing/destroying/combusting or otherwise destructive process. In certain embodiments, slurries, sprays, coatings, wires, strips, or sheets of materials can be used. Unwanted material can be removed for disposable or recycling by use of blowers, vacuum systems, sweeping, vibrating, shaking, tipping, or inversion of thebed 146.
• In addition to material handling components, thearticle processing unit 140 can include components for holding and supporting 3D structures, mechanisms for heating or cooling the chamber, auxiliary or supporting optics, and sensors and control mechanisms for monitoring or adjusting material or environmental conditions. The article processing unit can, in whole or in part, support a vacuum or inert gas atmosphere to reduce unwanted chemical interactions as well as to mitigate the risks of fire or explosion (especially with reactive metals).
• Control processor 150 can be connected to control any components ofadditive manufacturing system 100. Thecontrol processor 150 can be connected to variety of sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate operation. A wide range of sensors, including imagers, light intensity monitors, thermal, pressure, or gas sensors can be used to provide information used in control or monitoring. The control processor can be a single central controller, or alternatively, can include one or more independent control systems. Thecontroller processor 150 is provided with an interface to allow input of manufacturing instructions. Use of a wide range of sensors allows various feedback control mechanisms that improve quality, manufacturing throughput, and energy efficiency.
• FIG. 1B is a cartoon illustrating abed 146 that supportsmaterial 144. Using a series of sequentially applied, two-dimensional patterned energy beam images (squares in dotted outline 124), astructure 149 is additively manufactured. As will be understood, image patterns having non-square boundaries can be used, overlapping or interpenetrating images can be used, and images can be provided by two or more energy patterning systems. In other embodiments, images can be formed in conjunction with directed electron or ion beams, or with printed or selective spray systems.
• FIG. 2 is a flow chart illustrating one embodiment of an additive manufacturing process supported by the described optical and mechanical components. Instep 202, material is positioned in a bed, chamber, or other suitable support. The material can be a powder capable of being melted, fused, sintered, induced to change crystal structure, have stress patterns influenced, or otherwise chemically or physically modified to form structures with desired properties.
• Instep 204, unpatterned energy is emitted by one or more energy emitters, including but not limited to solid state or semiconductor lasers, or electrical power supply flowing electrons down a wire. In step 206, the unpatterned energy is shaped and modified (e.g. intensity modulated or focused). Instep 208, this unpatterned energy is patterned, with energy not forming a part of the pattern being handled in step 210 (this can include conversion to waste heat, or recycling as patterned or unpatterned energy). Instep 212, the patterned energy, now forming a two-dimensional image is relayed toward the material. Instep 214, the image is applied to the material, building a portion of a 3D structure. These steps can be repeated (loop 218) until the image (or different and subsequent image) has been applied to all necessary regions of a top layer of the material. When application of energy to the top layer of the material is finished, a new layer can be applied (loop 216) to continue building the 3D structure. These process loops are continued until the 3D structure is complete, when remaining excess material can be removed or recycled.
• FIG. 3A is one embodiment of anadditive manufacturing system 300 that uses multiple semiconductor lasers as part of anenergy patterning system 310. Acontrol processor 350 can be connected to variety of sensors, actuators, heating or cooling systems, monitors, and controllers to coordinate operation ofmultiple lasers 312,light patterning unit 316, andimage relay 320, as well as any other component ofsystem 300. These connections are generally indicated by a dottedoutline 351 surrounding components ofsystem 300. As will be appreciated, connections can be wired or wireless, continuous or intermittent, and include capability for feedback (for example, thermal heating can be adjusted in response to sensed temperature). Themultiple lasers 312 can emit abeam 301 of light at a 1000 nm wavelength that, for example, is 90 mm wide by 20 mm tall. Thebeam 301 is resized by imagingoptics 370 to createbeam 303.Beam 303 is 6 mm wide by 6mm tall, and is incident on light homogenization device 372 which blends light together to create blendedbeam 305.Beam 305 is then incident onimaging assembly 374 which reshapes the light intobeam 307 and is then incident on hotcold mirror 376. Themirror 376 allows 1000 nm light to pass, but reflects 450nm light. Alight projector 378 capable of projecting low power light at 1080p pixel resolution and 450nm emitsbeam 309, which is then incident on hotcold mirror 376.Beams 307 and 309 overlay inbeam 311, and both are imaged onto optically addressedlight valve 380 in a 20mm wide, 20mm tall image. Images formed from the homogenizer 372 and theprojector 378 are recreated and overlaid onlight valve 380.
• The optically addressedlight valve 380 is stimulated by the light (typically ranging from 400-500 nm) and imprints a polarization rotation pattern in transmittedbeam 313 which is incident uponpolarizer 382. Thepolarizer 382 splits the two polarization states, transmitting p-polarization intobeam 317 and reflecting s-polarization intobeam 315 which is then sent to abeam dump 318 that handles the rejected energy. As will be understood, in other embodiments the polarization could be reversed, with s-polarization formed intobeam 317 and reflecting p-polarization intobeam 315.Beam 317 enters thefinal imaging assembly 320 which includesoptics 384 that resize the patterned light. This beam reflects off of amovable mirror 386 tobeam 319, which terminates in a focused image applied tomaterial bed 344 in anarticle processing unit 340. The depth of field in the image selected to span multiple layers, providing optimum focus in the range of a few layers of error or offset.
• Thebed 390 can be raised or lowered (vertically indexed) withinchamber walls 388 that containmaterial 344 dispensed bymaterial dispenser 342. In certain embodiments, thebed 390 can remain fixed, and optics of thefinal imaging assembly 320 can be vertically raised or lowered. Material distribution is provided by asweeper mechanism 392 that can evenly spread powder held inhopper 394, being able to provide new layers of material as needed. An image 6 mm wide by 6 mm tall can be sequentially directed by themovable mirror 386 at different positions of the bed.
• When using a powdered ceramic or metal material in thisadditive manufacturing system 300, the powder can be spread in a thin layer, approximately 1-3 particles thick, on top of a base substrate (and subsequent layers) as the part is built. When the powder is melted, sintered, or fused by a patternedbeam 319, it bonds to the underlying layer, creating a solid structure. The patternedbeam 319 can be operated in a pulsed fashion at 40 Hz, moving to the subsequent 6 mm x 6 mm image locations at intervals of 10 ms to 0.5 ms (with 3 to 0.1 ms being desirable) until the selected patterned areas of powder have been melted. Thebed 390 then lowers itself by a thickness corresponding to one layer, and thesweeper mechanism 392 spreads a new layer of powdered material. This process is repeated until the 2D layers have built up the desired 3D structure. In certain embodiments, thearticle processing unit 340 can have a controlled atmosphere. This allows reactive materials to be manufactured in an inert gas, or vacuum environment without the risk of oxidation or chemical reaction, or fire or explosion (if reactive metals are used).
• FIG. 3B illustrates in more detail operation of thelight patterning unit 316 ofFIG. 3A. As seen inFIG. 3B, a representative input pattern 333 (here seen as the numeral "9") is defined in an 8x12 pixel array of light projected asbeam 309 towardmirror 376. Each grey pixel represents a light filled pixel, while white pixels are unlit. In practice, each pixel can have varying levels of light, including light-free, partial light intensity, or maximal light intensity. Unpatterned light 331 that formsbeam 307 is directed and passes through a hot/cold mirror 376, where it combines with patternedbeam 309. After reflection by the hot/cold mirror 376, the patternedlight beam 311 formed from overlay ofbeams 307 and 309 inbeam 311, and both are imaged onto optically addressedlight valve 380. The optically addressedlight valve 380, which would rotate the polarization state ofunpatterned light 331, is stimulated by the patternedlight beam 309, 311 to selectively not rotate the polarization state ofpolarized light 307, 311 in the pattern of the numeral "9" intobeam 313. The unrotated light representative ofpattern 333 inbeam 313 is then allowed to pass throughpolarizer mirror 382 resulting inbeam 317 andpattern 335. Polarized light in a second rotated state is rejected bypolarizer mirror 382, intobeam 315 carrying thenegative pixel pattern 337 consisting of a light-free numeral "9".
• Other types of light valves can be substituted or used in combination with the described light valve. Reflective light valves, or light valves base on selective diffraction or refraction can also be used. In certain embodiments, non-optically addressed light valves can be used. These can include but are not limited to electrically addressable pixel elements, movable mirror or micro-mirror systems, piezo or micro-actuated optical systems, fixed or movable masks, or shields, or any other conventional system able to provide high intensity light patterning. For electron beam patterning, these valves may selectively emit electrons based on an address location, thus imbuing a pattern on the beam of electrons leaving the valve.
• FIG. 3C is one embodiment of an additive manufacturing system that includes a switchyard system enabling reuse of patterned two-dimensional energy. Similar to the embodiment discussed with respect toFIG. 1A, anadditive manufacturing system 220 has an energy patterning system with anenergy source 112 that directs one or more continuous or intermittent energy beam(s) towardbeam shaping optics 114. After shaping, the beam is two-dimensionally patterned by anenergy patterning unit 230, with generally some energy being directed to a rejectedenergy handling unit 222. Patterned energy is relayed by one of multiple image relays 232 toward one or morearticle processing units 234A, 234B, 234C, or 234D, typically as a two-dimensional image focused near a movable or fixed height bed. The bed (with optional walls) can form a chamber containing material dispensed by material dispenser. Patterned energy, directed by the image relays 232, can melt, fuse, sinter, amalgamate, change crystal structure, influence stress patterns, or otherwise chemically or physically modify the dispensed material to form structures with desired properties.
• In this embodiment, the rejected energy handling unit has multiple components to permit reuse of rejected patterned energy.Relays 228A, 228B, and 22C can respectively transfer energy to anelectricity generator 224, a heat/coolthermal management system 225, or anenergy dump 226. Optionally,relay 228C can direct patterned energy into theimage relay 232 for further processing. In other embodiments, patterned energy can be directed byrelay 228C, to relay 228B and 228A for insertion into the energy beam(s) provided byenergy source 112. Reuse of patterned images is also possible usingimage relay 232. Images can be redirected, inverted, mirrored, sub-patterned, or otherwise transformed for distribution to one or more article processing units. 234A-D. Advantageously, reuse of the patterned light can improve energy efficiency of the additive manufacturing process, and in some cases improve energy intensity directed at a bed, or reduce manufacture time.
• FIG. 3D is acartoon 235 illustrating a simple geometrical transformation of a rejected energy beam for reuse. Aninput pattern 236 is directed into an image relay 237 capable of providing a mirrorimage pixel pattern 238. As will be appreciated, more complex pixel transformations are possible, including geometrical transformations, or pattern remapping of individual pixels and groups of pixels. Instead of being wasted in a beam dump, this remapped pattern can be directed to an article processing unit to improve manufacturing throughput or beam intensity.
• FIG. 3E is acartoon 235 illustrating multiple transformations of a rejected energy beam for reuse. Aninput pattern 236 is directed into a series of image relays 237B-E capable of providing apixel pattern 238.
• FIG. 3F and 3G illustrates a non-light basedenergy beam system 240 that includes a patternedelectron beam 241 capable of producing, for example, a "P" shaped pixel image. A high voltageelectricity power system 243 is connected to an optically addressable patternedcathode unit 245. In response to application of a two-dimensional patterned image byprojector 244, thecathode unit 245 is stimulated to emit electrons wherever the patterned image is optically addressed. Focusing of the electron beam pattern is provided by animage relay system 247 that includesimaging coils 246A and 246B. Final positioning of the patterned image is provided by adeflection coil 248 that is able to move the patterned image to a desired position on a bed ofadditive manufacturing component 249.
• In another embodiment supporting light recycling and reuse, multiplex multiple beams of light from one or more light sources are provided. The multiple beams of light may be reshaped and blended to provide a first beam of light. A spatial polarization pattern may be applied on the first beam of light to provide a second beam of light. Polarization states of the second beam of light may be split to reflect a third beam of light, which may be reshaped into a fourth beam of light. The fourth beam of light may be introduced as one of the multiple beams of light to result in a fifth beam of light. In effect, this or similar systems can reduce energy costs associated with an additive manufacturing system. By collecting, beam combining, homogenizing and re-introducing unwanted light rejected by a spatial polarization valve or light valve operating in polarization modification mode, overall transmitted light power can potentially be unaffected by the pattern applied by a light valve. This advantageously results in an effective re-distribution of the light passing through the light valve into the desired pattern, increasing the light intensity proportional to the amount of area patterned.
• Combining beams from multiple lasers into a single beam is one way to increasing beam intensity. In one embodiment, multiple light beams, each having a distinct light wavelength, can be combined using either wavelength selective mirrors or diffractive elements. In certain embodiments, reflective optical elements that are not sensitive to wavelength dependent refractive effects can be used to guide a multiwavelength beam.
• Patterned light can be directed using movable mirrors, prisms, diffractive optical elements, or solid state optical systems that do not require substantial physical movement. In one embodiment, a magnification ratio and an image distance associated with an intensity and a pixel size of an incident light on a location of a top surface of a powder bed can be determined for an additively manufactured, three-dimensional (3D) print job. One of a plurality of lens assemblies can be configured to provide the incident light having the magnification ratio, with the lens assemblies both a first set of optical lenses and a second sets of optical lenses, and with the second sets of optical lenses being swappable from the lens assemblies. Rotations of one or more sets of mirrors mounted on compensating gantries and a final mirror mounted on a build platform gantry can be used to direct the incident light from a precursor mirror onto the location of the top surface of the powder bed. Translational movements of compensating gantries and the build platform gantry are also able to ensure that distance of the incident light from the precursor mirror to the location of the top surface of the powder bed is substantially equivalent to the image distance. In effect, this enables a quick change in the optical beam delivery size and intensity across locations of a build area for different powdered materials while ensuring high availability of the system.
• In certain embodiments, a plurality of build chambers, each having a build platform to hold a powder bed, can be used in conjunction with multiple optical-mechanical assemblies arranged to receive and direct the one or more incident energy beams into the build chambers. Multiple chambers allow for concurrent printing of one or more print jobs inside one or more build chambers. In other embodiments, a removable chamber sidewall can simplify removal of printed objects from build chambers, allowing quick exchanges of powdered materials. The chamber can also be equipped with an adjustable process temperature controls.
• In another embodiment, one or more build chambers can have a build chamber that is maintained at a fixed height, while optics are vertically movable. A distance between final optics of a lens assembly and a top surface of powder bed a may be managed to be essentially constant by indexing final optics upwards, by a distance equivalent to a thickness of a powder layer, while keeping the build platform at a fixed height. Advantageously, as compared to a vertically moving the build platform, large and heavy objects can be more easily manufactured, since precise micron scale movements of the build platform are not needed. Typically, build chambers intended for metal powders with a volume more than ~ 0.1 - 0.2 cubic meters (i.e., greater than 100 - 200 liters or heavier than 500 - 1,000 kg) will most benefit from keeping the build platform at a fixed height.
• In one embodiment, a portion of the layer of the powder bed may be selectively melted or fused to form one or more temporary walls out of the fused portion of the layer of the powder bed to contain another portion of the layer of the powder bed on the build platform. In selected embodiments, a fluid passageway can be formed in the one or more first walls to enable improved thermal management.
• Improved powder handling can be another aspect of an improved additive manufacturing system. A build platform supporting a powder bed can be capable of tilting, inverting, and shaking to separate the powder bed substantially from the build platform in a hopper. The powdered material forming the powder bed may be collected in a hopper for reuse in later print jobs. The powder collecting process may be automated, and vacuuming or gas jet systems also used to aid powder dislodgement and removal
• Some embodiments of the disclosed additive manufacturing system can be configured to easily handle parts longer than an available chamber. A continuous (long) part can be sequentially advanced in a longitudinal direction from a first zone to a second zone. In the first zone, selected granules of a granular material can be amalgamated. In the second zone, unamalgamated granules of the granular material can be removed. The first portion of the continuous part can be advanced from the second zone to a third zone, while a last portion of the continuous part is formed within the first zone and the first portion is maintained in the same position in the lateral and transverse directions that the first portion occupied within the first zone and the second zone. In effect, additive manufacture and clean-up (e.g., separation and/or reclamation of unused or unamalgamated granular material) may be performed in parallel (i.e., at the same time) at different locations or zones on a part conveyor, with no need to stop for removal of granular material and/or parts.
• In another embodiment, additive manufacturing capability can be improved by use of an enclosure restricting an exchange of gaseous matter between an interior of the enclosure and an exterior of the enclosure. An airlock provides an interface between the interior and the exterior; with the interior having multiple additive manufacturing chambers, including those supporting power bed fusion. A gas management system maintains gaseous oxygen within the interior at or below a limiting oxygen concentration, increasing flexibility in types of powder and processing that can be used in the system.
• In another manufacturing embodiment, capability can be improved by having a 3D printer contained within an enclosure, the printer able to create a part having a weight greater than or equal to 2,000 kilograms. A gas management system may maintain gaseous oxygen within the enclosure at concentrations below the atmospheric level. In some embodiments, a wheeled vehicle may transport the part from inside the enclosure, through an airlock, since the airlock operates to buffer between a gaseous environment within the enclosure and a gaseous environment outside the enclosure, and to a location exterior to both the enclosure and the airlock.
• Other manufacturing embodiments involve collecting powder samples in real-time in a powder bed fusion additive manufacturing system. An ingester system is used for in-process collection and characterizations of powder samples. The collection may be performed periodically and the results of characterizations result in adjustments to the powder bed fusion process. The ingester system can optionally be used for one or more of audit, process adjustments or actions such as modifying printer parameters or verifying proper use of licensed powder materials.
• Yet another improvement to an additive manufacturing process can be provided by use of a manipulator device being according to the invention a robot arm that allows for the manipulation of parts that would be difficult or impossible for a human to move is described. The manipulator device according to the present invention comprises a robot arm. The manipulator device can grasp various permanent or temporary additively manufactured manipulation points on a part to enable repositioning or maneuvering of the part.
• FIG. 4A illustrates an additively manufactured collection ofparts 400, with eachpart 402 supported by a surrounding additively manufacturedmanipulation point 404. As is evident from the Figure, a large variety of parts can be additively manufactured and attached with removable structures that support each part and allow pickup and maneuvering of theparts 400 with one or more manipulators (not shown). In the disclosed Figure, an outer perimeter surrounding theparts 400 would normally be a target for engagement with the manipulator, but in some embodiments, interior manipulation points can be engaged.
• FIG. 4B illustrates another additively manufacturedstructure 410 that forms a portion of an aerial drone vehicle. Thestructure 412 can be supported by engagement of a manipulator with one or more manipulation points 414.
• FIG. 5A illustrates anadditive manufacturing system 500 that includes apowder chamber 502 with apowder bed 504. Thesystem 500 can also include aprocessing platform 520, which can be a designated processing area, another powder chamber, a coating station, a conveyor, a shipping container, or any other needed manufacturing system component. Thesystem 500 also includes arobot arm 510 withmanipulator 512 capable of grasping apart 530 by its additively manufacturedmanipulation point 532. Sensor systems 534 can be mounted on therobot arm 510, or alternatively, on, in, or near thepowder chamber 502.
• While a six degree of freedom single robot arm with clamping graspers is a manipulation device shown in the Figure, other robot arms can be used. The manipulation device according to the present invention comprises a robot arm. A manipulation device can be mounted beside, on, near, or within thepowder chamber 502. Alternatively, a manipulation device can be movably mounted on rails over, near, or positioned within the powder chamber. Multiple manipulation devices can be used in some embodiments
• A manipulation device can include position, depth, laser scanning, orsimilar sensor systems 514. Sensors can be mounted on or near the manipulator, elsewhere on the robot arm, or on, near, or within the powder chamber orprocessing platform 520. In certain embodiments, a sensor can be movable, with hinged, rail, hydraulic piston, or other suitable actuating mechanisms used to rotate, elevate, depress, oscillate, or laterally scan the sensor. In certain embodiments, conventional RGB CMOS or CCD sensors can be used, alone or in combination specialized depth sensors or optical edge tracking sense systems. Embodiments can be selected to improve 3D localization of a part, including identification and use guides, markers, or other detectable positioning indicia.
• FIG. 5B illustrates the system described with respect toFIG. 5A, with therobot arm 510 lifting and reorienting apart 530 by one of its additively manufactured manipulation points 532. In some embodiments, thepart 530 can be lifted, rotated, linearly translated, and set back onto thepowder bed 504 for further processing. Such embodiments are not covered by the appended claims.
• FIG. 5C illustrates the system described with respect toFIG. 5A, with therobot arm 510 lifting and reorienting apart 530 by one of its additively manufactured manipulation points 532. In this embodiment, thepart 530 lifted, rotated, and set onto theprocessing platform 520 for further processing. Such embodiments are covered by the appended claims.
• FIG. 6 illustrates apart 600 including various possible additively manufactured robot manipulation points.Part 600 supports various projecting structures (i.e. 602, 604, 606, 608, and 614), as well as internal structures or cavities (i.e. 610, 612, and 616), capable of acting as robot manipulation points. In the Figure,structure 602 is a lunate tab having two narrow connection points topart 600. The tab portion allows for easy engagement with manipulators having nipping or pinching graspers, while the narrow connection points simplify removal of thestructure 602 by mechanical clipping, sawing, punching, or drilling; or by directed energy beams. Similarly,pin 604 is a small projecting structure capable of being engaged by nipping or pinching graspers, or by a "bit" holding type engagement system that surrounds and constricts to hold thepin 602.Rectangular tab 606 is attached at a single narrow point, allowing some embodiments of the manipulator to twist and break free the tab after the part has been moved to a desired area/position.Plate 608, again attached at two points to simplify later removal by mechanical clipping or energy beams, is relatively long and broad to simplify the engagement by the manipulator.
• Additive manufacturing of thepart 600 can be designed to include depressions, lands, cavities, holes, or other internally defined structures that do not greatly affect part function, but improve reliability of engagement with the robot arm. For example, prismatic lockingcavity 610 can guide a pin or clamp system into engagement with the cavity. Alternatively, spreading grippers can be used to engage anotch 612 defined in thepart 600. Cavities oropenings 616 can also be defined in removable projectingtabs 614 if needed. In some embodiments, cavities or opening in a substantially additively manufactured part can be defined by subtractive machining, drilling, punching, or removal of material be etching or directed energy beams. In certain other embodiments, after use the cavities can be filled using additive manufacturing techniques, by use of thermoset plastics, or any other suitable fill technique.
• In some examples, not defined by the invention, two or three-dimensional positioning of thepart 600 can be improved by use of imaging or other optic sensors that identify precise position of the part using projecting tab or cavity position. In embodiments according to the invention, marking optical guides orindicia 620 are additively formed or mechanically or laser inscribed on the projecting structure or the part itself to improved guidance for engagement of 3D positioning after movement.
• FIG. 7 is aflowchart 700 illustrating one embodiment of a method for additive manufacturing that uses manipulation points. Instep 702, material is positioned on a powder bed in a powder chamber. Instep 704, using directed beams of two-dimensionally patterned energy, a part is manufactured that includes one or more manipulation points. Instep 706, the manipulator can engage the manipulation point, and lift the part away from a powder bed. The part is moved (step 708) to a new processing area away from the powder bed and chamber. In anoptional step 710, the manipulation point can be removed (e.g. a projecting tab is mechanically clipped), or infilled (e.g. additively defined holes or cavities filled with an epoxy resin). Inoptional step 712, parts moved to a new position can have additional material positioned and additively manufactured thereon.
• Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed.

Claims (6)

1. A manufacturing method comprising the steps of:

   providing a powdered material;

   providing an energy source (112) that can produce an energy beam;

   directing the energy beam from the energy source (112) toward an energy beam patterning unit (116, 230) to form a two-dimensional patterned energy beam (241);

   directing the two-dimensional patterned energy beam (241) against the powdered material to melt or sinter or fuse the powdered material to form a part (402) having a temporary or permanent additively manufactured structure (410) acting as a manipulation point (404);

   additively forming optical guides or indicia (620) on a projecting structure or the part (402); and

   moving the part (402) using a manipulator device (512) to grasp the manipulation point (404), wherein the optical guide or indicia (620) provides guidance of 3D positioning for engagement of the manipulator device (512) with the part (402) after movement, the moving comprising lifting the part (402) by the manipulation point (404) away from a power bed (504) and setting the part (402) on a designated processing area for further processing;
   wherein the manipulator device further comprises a robot arm (510).
2. The method of claim 1, further comprising the step of removing the manipulation point (404).
3. The method of claim 1, wherein:

   the manipulation point (404) projects from the part (402); and

   the method further comprises removing the manipulation point (404).
4. The method of claim 1, wherein:

   the manipulation point (404) comprises an additively defined hole or cavity; and

   the method further comprises infilling the additively defined hole or cavity.
5. The method of claim 1, wherein the powdered material is at least one of a metal, ceramic, and plastic.
6. The method of claim 5, wherein the two-dimensional patterned energy beam (241) is formed from multiple semiconductor lasers directed at an optically addressed light valve.

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